There any many useful resources and some awesome guides like roadmap.sh which gives good perspective of where we stand. Apart from those there are few other blogs that I would like to highlight, like:

• Theodo blog about JS library tree shaking and related module concept.
• Josh Comeau's blog on z-index stacking introduced me to his CSS courses.
• michaelmang
• Guide to help choose frameworks | kruschecompany.com
• usehooks.com
• Understanding the core JavaScript | dmitrysoshnikov.com
• https://www.patterns.dev/

React Native

• React Native - Beyond Basics | kadikraman.github.io

Webpack

• Node v8 deep-dive webpack 5 fix | engineering.tines.com

Mobile browsers

• MDN | Detect tab switches and browser app sleep/awake cycle

Build tools

• Broccoli blog gives overall architecture and comparison with gulp and grunt.
• Compiling to JavaScript, and Debugging with Source Maps, along with Source Map Revision 3 Proposal
• New insights on modern frameworks, 2017